46 ¶ While he yet talked to the people, behold, his mother and his brethren stood without, desiring to speak with him. 47 Then one said unto him, Behold, thy mother and thy brethren stand without, desiring to speak with thee. 48 But he answered and said unto him that told him, Who is my mother? and who are my brethren? 49 And he stretched forth his hand toward his disciples, and said, Behold my mother and my brethren! 50 For whosoever shall do the will of my Father which is in heaven, the same is my brother, and sister, and mother.
31 ¶ There came then his brethren and his mother, and, standing without, sent unto him, calling him. 32 And the multitude sat about him, and they said unto him, Behold, thy mother and thy brethren without seek for thee. 33 And he answered them, saying, Who is my mother, or my brethren? 34 And he looked round about on them which sat about him, and said, Behold my mother and my brethren! 35 For whosoever shall do the will of God, the same is my brother, and my sister, and mother.
Matthew 12:48–50. Those Who Do the Will of the Father Belong to His Eternal Family In these verses, the Savior took the arrival of His family as an opportunity to teach that those who do the will of Heavenly Father belong to His eternal family. Elder Bruce R. McConkie said of the Savior’s words: “The blessings of heaven are available—freely, without money and without price—to all men. All men cannot be born into this world as the sons of God, after the manner of the flesh, but all, through righteousness, can be adopted into the family of the Eternal God and become joint-heirs with Christ of the fullness of the glory and power of the Father” (Mortal Messiah, 2:227). In this dispensation, the Savior again taught this principle: “Verily, verily, I say unto you, that as many as receive me, to them will I give power to become the sons of God, even to them that believe on my name” (D&C 11:30).Chapter 4: Matthew 8–12https://www.churchofjesuschrist.org/study/manual/new-testament-student-manual/introduction-to-matthew/chapter-4?id=title39,p80-p81&lang=eng#title39